The focus of the proposed program is to evaluate the feasibility of a new testing approach for the identification of individuals with salt sensitivity during routine physical examination. The technology we plan to utilize is surface-enhanced Raman scattering (SERS), a well-known analytical technique for precise lab identification of organic compounds. We propose to identify the chemical markers for salt sensitivity excreted in the urine by SERS Raman spectroscopy analysis. The overall aim is to develop a portable on-site device versatile enough so that it can be used for immediate identification of chemical markers in salt sensitive individuals, markers expected to be present as trace amounts in urine, from samples collectible on-site in the course of a physical examination to allow appropriate intervention and/or treatment in a timely fashion. Our revised Phase 1 program is designed to assess the capability of Raman to quantify the levels of a range of representative markers for salt sensitivity in a simple model urine sample with varying concentrations of selected representative marker materials present. Additional initial testing will be performed on actual urine samples for a first evaluation of the sensitivity and selectivity of the Raman monitoring approach. In Phase 2 we would expand the process to on-site urinalysis paralleling actual on-site examination and clinical testing procedures.